Case discussion: How would you treat this patient? [25 September]
This week we have an interesting case from Dr Colin Armstrong. An elderly lady presented for a skin check and had a suspicious lesion on calf muscle as shown.
We have the clinical and dermoscopy picture below. What do you think about the lesion? What are the next steps you would take to treat this patient?
Dr Colin did 2 x shave biopsies, and below is the result. What next?
Clinical Notes: Histopathology – shave biopsy. (Right) posterior calf – ?atypical naevus 2 frags. A surgical diagram is provided indicating lighter zone ?solar lentigo and darker zone dermoscopic grey.
The specimen container is labelled ‘Right posterior calf‘. The specimen consists of two portions. The first is a shave of skinmeasuring14x14x1mm. Theskinsurfacerevealsabrownvariegatedpatchmeasuring13x11mm. The second piece is a shave of skin measuring 15x12x1mm. The skin surface reveals a poorly defined light brown scaly lesion measuring 10x10mm.
Blocking Details: 1A 1st portion dissected into 5 pieces, blocked in toto; 1B 2nd portion dissected into 4 portions, blocked in toto.
Both portions of tissue show a broad atypical junctional melanocytic proliferation with areas of crowding and confluent growth,and patchy pagetoid spread into the over lying epidermis. The features are of malignant melanoma with mixed features of lentigo maligna and superficial spreading subtypes. Occasional small nests of atypical melanocytes are present within the papillary dermis. Some of these are favoured as cross cutting of junctional nests, however, also present are occasional small crowded groups and single atypical melanocytes within the papillary dermis best regarded as early invasion (Clark level 2, Breslow thickness 0.2mm). There are variable changes of established and inflammatory regression within the superficial dermis. Ulceration is not seen. The in situ component extends to edges of both portions of tissue and the invasive component lies >2mm from edge margins and 0.2mm from the deep margin.
RIGHT POSTERIOR CALF – INVASIVE MALIGNANT MELANOMA (CLARK LEVEL 2, BRESLOW THICKNESS 0.2MM), OF MIXED LENTIGO MALIGNA AND SUPERFICIAL SPREADING TYPES, EXTENDING TO EDGES OF BOTH PORTIONS OF TISSUE.
Here is what Colin did for the formal excision and here is the final result.
Clinical Notes: Histopathology. WLE-(Right) posterior calf-level 1 and 2 melanoma on SBx.
The specimen container is labelled ‘Right post calf‘. The specimen consists of a tear drop shaped portion of skin and subjacent tissues measuring 60 x 35 x 13mm. Examination of the skin surface reveals a partially healed scar from previous biopsy measuring 20 x 18mm. A marking suture is present at the tip designated 12 o’clock. The 3 o’clock margin is inked green and 9 o’clock margin is inked black.
Blocking Details: 1A 1LS 12 o’clock; 1B-1H each 1TS from the centre, each TS bisected; 1I 1LS 6 o’clock.
The sections show a focus of residual Clark Level 1 (in-situ) malignant melanoma. No residual invasive component is identified. There is an adjacent small population of bland dermal naevus cells in keeping with a component of benign intradermal naevus. The excision appears complete and residual in-situ melanoma has a clearance of 6mm from the closest peripheral margin (9 o’clock). The 12, 3 and 6 o’clock margins are >10mm.
WIDE LOCAL EXCISION, RIGHT POSTERIOR CALF:
– RESIDUAL CLARK LEVEL 1 (IN-SITU) MALIGNANT MELANOMA AND AN INCIDENTAL FOCUS OF BENIGN INTRADERMAL NAEVUS, COMPLETE EXCISION.
We encourage you to participate in the case discussions and submit your own clinical images and questions so we can all learn together.